Superexchange interactions through dicyanamide

INOR 317

Katie J. Heroux, kheroux@ucsd.edu, Antonio G. DiPasquale, Arnold L. Rheingold, and David N. Hendrickson. Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093
Very recently the dicyanamide ion, N(CN)2-, has been incorporated as a bridging species in various transition metal complexes. Several [Cu2(tren)2(dca)]Y3 dimers, where tren is 2, 2′, 2′′-triaminotriethylamine, dca- is the dicyanamide anion, and Y- is ClO4-, BF4-, PF6-, or BPh4-, have been prepared to study their magnetic exchange pathways. The synthesis, crystal structure, and magnetic properties of [Cu2(tren)2(dca)](BPh4)3 (1) and the monomer [Cu(tren)(dca)](BPh4) (2) are reported and discussed. Complex 1 exhibits weak antiferromagnetic exchange (J = -4 cm-1) whereas complex 2 shows no exchange, thus confirming the dca- bridge as the superexchange pathway in this system. The efficiency of the dca- bridge as a magnetic exchange pathway has become of recent interest in the area of single-molecule magnets (SMMs). Greater chemical control over the magnetic exchange interactions between SMMs could lead to new nanomagnets with attractive physical properties.